/usr/share/maven-repo/org/codehaus/plexus/plexus-compiler-manager/debian/plexus-compiler-manager-debian.jar is in libplexus-compiler-java 1.6-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/maven-repo/org/codehaus/plexus/plexus-compiler-manager/debian/../1.6/plexus-compiler-manager-1.6.jar